The use of microviscometry to study polymer dissolution from solid dispersion drug delivery systems

Area of Science:

• Pharmaceutical Sciences
• Materials Science

Background:

• Solid dispersions enhance drug dissolution, with polyvinylpyrrolidone (PVP) a common carrier.
• Mechanisms of drug release from solid dispersions require understanding the dissolution behavior of both drug and polymer.

Purpose of the Study:

• To investigate drug release mechanisms from ibuprofen-PVP solid dispersions.
• To assess the utility of microviscometry in studying drug release from polymeric systems.

Main Methods:

• Microviscometry was employed to measure viscosity changes in the dissolution medium.
• The rolling/falling ball principle was used to determine dynamic and kinematic viscosity.
• Drug release and polymer dissolution were monitored simultaneously using a USP dissolution apparatus.

Main Results:

• Drug release from ibuprofen-PVP solid dispersions closely correlated with polymer dissolution.
• Microviscometry demonstrated sensitivity in detecting polymer dissolution alongside drug release.
• The technique proved easy to use in conjunction with standard dissolution equipment.

Conclusions:

• Microviscometry is a valuable tool for elucidating drug release mechanisms from solid dispersions.
• The study highlights the close link between polymer dissolution and drug release kinetics.
• This method offers a sensitive and practical approach for characterizing polymeric drug delivery systems.